* https://review.openstack.org/#/c/600517 introduces undercloud_container_cli
to choose docker/podman container runtime. This changes introduces to use
both docker/podman for running tempest tests.
* Tempest user does not have permission to create tempest workspace let's
create the tempest workspace and own it with the tempest user.
* Introducing tempest_data directory to keep tempest related data
which can be used by tempestconf and tempest run to tests
* Cleaned up stuff which is not necessary for tempest container.
Depends-On: https://review.openstack.org/#/c/614664/
Change-Id: I1b19b2580d1d4c9844e9221f18b23655b36b5a23